Solid inkjet printing technology includes ink in solid form which is heated to a printing temperature and ejected from a printhead nozzle by a plurality of ejectors (actuators). The ink can be deposited, for example, directly onto a print medium or onto a media transfer device such as a heated rotating drum which transfers the ink through physical contact with the print medium.
To provide a suitable print quality using solid inkjet printers, it is desirable to dispense ink from the ejectors at a temperature which is within a few degrees of a target temperature. The target temperature for solid ink can be between about 105° C. and 140° C. The temperature of the melted ink can be maintained by heating the printhead with a heated mass such as a flexible polyimide thin film layer with metal traces of gold or copper on the polyimide surface. The heater is assembled using adhesive layers, and heats the printhead which transfers the heat through contact with the ink as it flows through channels in the printhead. In another design, an inkjet device can include heaters wrapped around ink tubes leading to the print head. In yet another particular design, as described in U.S. Pat. No. 8,083,323 which is commonly assigned herewith and incorporated by reference in its entirety, a heater can be formed on a semiconductor wafer substrate and the ejector is formed using semiconductor manufacturing techniques.